1. Field of the Invention
The present invention generally relates to a power head of an outboard motor. More particularly, the present invention relates to an improved arrangement of engine equipment.
2. Description of Related Art
A typical outboard motor comprises a drive unit and a bracket assembly. The drive unit primarily includes a power head, a driveshaft housing and a lower unit. The power head incorporates an internal combustion engine surrounded by a protective cowling. The driveshaft housing depends from the power head and supports a driveshaft that is driven by an output shaft of the engine. The lower unit depends from the driveshaft housing and carries a propulsion device such as a propeller. The propeller is attached to a propulsion shaft that is driven by the driveshaft. The propulsion shaft extends through at least a portion of the lower unit.
The bracket assembly normally comprises a swivel bracket and a clamping bracket. The swivel bracket supports the drive unit for pivotal movement about a generally vertically extending steering axis. The clamping bracket is mounted on an associated watercraft and supports the swivel bracket for pivotal movement of the outboard motor and the attached swivel bracket about a generally horizontally extending tilt axis.
The bracket assembly can include a hydraulic tilt and trim system that is provided between the swivel bracket and the clamping bracket to tilt the drive unit up and down about the tilt axis and also to adjust a trim position of the drive unit. The trim position affects the angle of attack of the propulsion device (i.e., the propeller) within the body of water in which the outboard motor is being operated. The hydraulic tilt system has a hydraulic pump that is usually actuated by an electric motor. The electric motor requires a tilt relay unit that supplies electric power to the motor from a power source such as a generator or a battery. The relay unit generally is relatively large.
The relay uniforms but one of a number of electrical components used in internal combustion powered engines. These electrical components are supplied with power from a battery, a generator or a combination of the two components. Each of the circuits supplying the power generally pass through at least one fuse to reduce the likelihood that a current spike flowing through the electric circuit will damage the electrical components. In the event a fuse blows, the fuse must be replaced for proper operation of the electrical components. For this purpose, a fuse puller often is provided within the confines of the outboard motor. For instance, the fuse puller can be mounted in an electrical equipment case in which the fuse puller is concealed from normal viewing. Thus, the user or service person may have search for the concealed fuse puller, which searching increasing servicing time and increases the frustration of a casual watercraft operator that simply needs to replace a fuse without a great deal of technical watercraft knowledge.
The engine is surrounded by the protective cowling assembly as noted above. As can be appreciated, the size and configuration of the outboard motor, which is often determined by the sizing of this cowling assembly, affects handling of the associated watercraft, among other things. For instance, an unduly wide outboard motor increases air resistance during movement of the watercraft through the water. However, the interior of the cowling assembly could be a suitable place for mounting the tilt relay unit because of the enclosed compartment that it forms. In other words, the tilt relay unit can be well-protected from splashing water by mounting the tilt relay within the cowling assembly.
On the other hand, positioning the rather large tilt relay unit within the cowling would seemingly increase the size of the power head, which preferably is as small as possible for the reasons discussed above. Placement of the tilt relay unit within the current cowling adjacent the current engine configuration would appear to be difficult because the reduced power head size results in minimal free space between an outer surface of the engine and an inner surface of the cowling assembly.
A need therefore exists for an improved outboard motor construction that can be provided with a tilt relay unit of a hydraulic tilt and trim system in good arrangement balance. In outboard motors featuring counter-flow engine configurations (i.e., those featuring an air intake passage and exhaust passage that communicate with a combustion chamber on the same side of the engine), another need exists for an improved outboard motor construction that better structures the components along the engine surfaces such that voids between the engine and the cowling can be reduced. For instance, the relatively empty space defined in the side of the engine opposite the intake and exhaust passages can be significantly reduced. A further need exists for an improved outboard motor construction that accommodates a fuse puller in a readily accessible and/or visible location
In accordance with one aspect of the present invention, an outboard motor comprises a drive unit and a bracket assembly. The drive unit has an internal combustion engine. The bracket assembly is adapted to be mounted on an associated watercraft. The bracket assembly supports the drive unit for pivotal movement about a generally horizontally extending tilt axis. A hydraulic tilt system is arranged to tilt the drive unit up and down. The tilt system includes a hydraulic pump and an electric motor that is capable of actuating the hydraulic pump. A relay unit supplies electric power to the electric motor based upon a control signal. The relay unit is disposed generally between the engine and the bracket assembly.
In accordance with another aspect of the present invention, an outboard motor comprises a drive unit and a bracket assembly. The drive unit has an internal combustion engine. The bracket assembly is adapted to be mounted on an associated watercraft. The bracket assembly supports the drive unit for pivotal movement about a generally horizontally extending tilt axis. The engine includes an air intake passage through which an air charge can be introduced to the combustion chamber. An exhaust passage receives exhaust gases from the combustion chamber. Both the air intake passage and the exhaust passage are disposed on the same side of the engine. At least two engine fixtures are disposed on the opposite side of the engine. The two engine fixtures comprise a large fixture and a small fixture. The small fixture is positioned closer to the bracket assembly than the large fixture.
In accordance with a further aspect of the present invention, an outboard motor comprises a drive unit and a bracket assembly. The drive unit has an internal combustion engine. The bracket assembly is adapted to be mounted on an associated watercraft and supporting the drive unit for pivotal movement about a generally horizontally extending tilt axis. A cover member covers over the engine at least in part. The engine includes a fuse unit arranged to contain at least one fuse. A fuse puller with which the fuse can be replaced is detachably affixed to the cover member.
In accordance with a still further aspect of the present invention, an outboard motor comprises a drive unit and a bracket assembly. The drive unit has an internal combustion engine. The bracket assembly is adapted to be mounted on an associated watercraft. The bracket assembly supports the drive unit for pivotal movement about a generally horizontally extending tilt axis. The engine included at least one combustion chamber. An air induction conduit communicates with the combustion chamber. A control valve is disposed within the air intake conduit. The control valve is adapted to adjust the air charge flow rate. A valve actuator is connected to the air intake conduit and is adapted to actuate the control valve when the atmospheric temperature is lower than a preset value.
For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. Further aspects, features and advantages of this invention will become apparent from the detailed description of the preferred embodiment which follows.